Metallization device and method

ABSTRACT

The present invention concerns a mmetallization device ( 1 ) for a substrate ( 2 ) by metallic material ( 3 ), comprising means ( 5 ) for generating heat suitable to melt said metallic material ( 3 ); means ( 4 ) for guiding said metallic material ( 3 ) suitable to bring said material in correspondence of said heat generating means ( 5 ); and means generating compressed air suitable to generate a compressed air jet (A) on said melt metallic material by said heat generation means ( 5 ), in order to nebulise the same so as to obtain a jet exiting from an outlet nozzle ( 6 ) and cooling nebulised particles of said metallic material ( 3 ), said jet exiting from said outlet nozzle ( 6 ) being directed on said substrate ( 2 ) so as to metalize it and said cooling being such to bring said particles from a melting state to a plastic state and at a temperature lower that the pyrolysis or decomposition temperature of said substrate ( 2 ). 
     The present invention also concerns a metallization method.

The present invention relates to a metallization device and method.

More specifically, the invention concerns to an innovation in the spray metallization field, already known for coating other metals, in order to protect them with respect to rust and other damages caused by atmospheric agents.

At present, it is not possible directly melting metals on materials such as wood, cloth, paper, plastics and on all those materials characterized by a common scientific datum, molecular decomposition and pyrolysis starting at a temperature of 220° C.

It was not possible until now transferring on said materials copper arriving from a direct melting t a thermal value of 1100° C., or brass melting at about 950° C., or simply zinc melting at 470° C., since these substrate materials would decompose and would be subjected to pyrolysis.

In view of the above, it is subject of the present invention that of suggesting a metallization device, and method for coating a generic material substrate with a low melting point or so called combustibles using metallic wires of dusts, oxides (ceramic), carbides, plastics.

It is further object of the present invention permitting a direct fusion of metal on materials the decomposition and pyrolysis of which starts at 220° C.

It is therefore specific object of the present invention a metallization device for a substrate by metallic material, comprising means for generating heat suitable to melt said metallic material; means for guiding said metallic material suitable to bring said material in correspondence of said heat generating means; and means generating compressed air suitable to generate a compressed air jet on said melt metallic material by said heat generation means, in order to nebulize the same so as to obtain a jet exiting from an outlet nozzle and cooling nebulized particles of said metallic material, said jet exiting from said outlet nozzle being directed on said substrate so as to metalize it and said cooling being such to bring said particles from a melting state to a plastic state and at a temperature lower that the pyrolysis or decomposition temperature of said substrate.

Always according to the invention, said .heat generation means can be of the electric arc kind.

Still according to the invention, said heat generation means can be of the oxyacetilenic combustion kind.

Furthermore, according to the invention, said device can comprise cooling means placed in correspondence of said outlet nozzle cooling said exiting jet.

Preferably, according to the invention, said cooling means can comprise a serpentine heat exchanger with refrigerating fluid placed in correspondence of the outlet nozzle.

Further, according to the invention, said device can comprise heat-adjustment means for adjusting temperature of said outlet jet.

Always according to the invention, said metallic material can be a metallic wire or dust.

It is further object of the present invention a method for metallization of a substrate comprising the following steps:

-   -   heating said metallic material bringing it at the fusion         temperature;     -   providing a compressed air jet on said melt metallic material so         as to nebulize the same material obtaining an outletting jet and         cooling the same, said cooling being such to bring said         particles from a melt state to a plastic state and at a         temperature lower than the pyrolysis or decomposition         temperature of said substrate;     -   directing said outlet jet on said substrate to be metalized.

Always according to the invention, said method can comprise the further steps:

-   -   further cooling said outlet jet; and     -   heat-adjusting said outlet jet.

Present invention will be now described for illustrative and not limitative purposes according to preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein,

FIG. 1 shows a metallization device according to the invention; and

FIG. 2 shows a metallic particle impacting with a substrate.

In the following it will be described, for exemplificative but not imitative purposes, the realization and metallization technique employing a spray metallization apparatus.

Making reference to FIG. 1, it is observed device 1 for metallization of a substrate 2, e.g. a wood, cloth, leather, plastics or paper substrate. A metallic wire 3 is provided in device 1, a wire comprised of metallization material, such as zinc, copper, aluminum, iron, silver, gold, tin and their alloys, inserted within suitable guides 4. Device 1 further comprises heating means bringing metallic wire 5 material at its melting point.

Finally, device also comprises means generating compressed air suitable to generate a compressed air jet A acting on the melt material.

Device 1 comprises, in correspondence of outlet jet 6, cooling means (not shown in the figure), such as a serpentine heat exchanger with refrigerating fluid, placed in correspondence of the nozzle 6. For cooling jet exiting from nozzle 6.

Carry-over material, from wire 3 (but that can also be dust), is heated by heating means 5, transformed into particles at the plastic state, that, projected at high speed, warped on substrate, creating lamellae that, solidifying, overlapping and fixedly coupling each other, create a coating with a lamellar structure.

Therefore, anchoring of material sprayed on substrate is not of the chemical—metallurgical kind, but of the mechanical kind. This permits making deposit of all wire or dust materials on different substrates (e.g. wood, plastics, graphite, steel, different alloys, ecc.).

During the deposit process, substrate reaches a temperature which is high but in any case lower than the molecular decomposition or pyrolysis temperature, that, by suitable solutions, can be kept under control by said cooling means or other thermo-adjustment means, or it can be maintained under the temperature that would cause physical or geometrical alterations of substrate.

Heating means 5 can be of the electric arc kind or of the oxyacetylene kind, exploiting thermal power developed by direct current electric arc between two wires, obtaining fusion of the same wires, while a compressed air or inert gas jet atomizes and sprays fuse particles on substrate.

In other words, in another embodiment, a wire shaped metal is inserted into an oxyacetilene gun, generating a thermal jet the temperature of which does not passes 1500° C.

A suitable system, such as means for generating compressed air, pushes metal to pass through the thermal zone, thus obtaining passage of metal from solid state to liquid state, and then, melt metal, thanks to gases deriving from combustion, is projected according to the same direction of the flame.

When liquid state particles meet the object along their trajectory, deposit realizing the metallic layer on the hit surface. A suitable choice of exposition time at the temperature and distance of material to be covered in the melting point determine success of application, permitting metallization with wished shape and thickness on combustibles materials the molecular decomposition and pyrolysis of which starts at 220° C.

FIG. 2 shows a metallic particle 7 before impacting with substrate 2 and a metallic particle 7′ after impact with a substrate 2. As it can be noted, incandescent material reduced at micro-parts reaches object to be metalized and deposits on surface obtaining a juxtaposition thickness.

By the same process, it is obtained that metals as zinc, copper bronze, brass, ecc. can be deposited on so called combustibles materials, such as plastic, wood, resins, ecc.

This method, permitting metallization of combustibles materials the pyrolysis of which occurs at 220° C., has the following main features:

-   -   application of an additional jet of compressed air on the gun,         refrigerated in order to obtain a rapid cooling of incandescent         particles hitting said low thermal sealing materials preventing         that the same fire, thus obtaining metallization of surface;     -   in some particle delicate workings, such as metallization of         tissues or of inflammable products with a small thickness, for         deposition method by direct fusion, it has been employed a         refrigerated plane or cooling means, further reducing cooling         time, thus obtaining the wished result.

An advantage of the present invention is that metallization operation can be carried out into “free air”, i.e. it is not necessary a pressurized atmosphere environment, permitting a low cost manufacturing.

A further advantage of the present invention is that of permitting the realization of metallic fusion on cloths or similar products to be used in the clothing field, including decorative accessories.

Another advantage of the present invention is that of permitting coating of wood standing finish, furnitures and equipments in the furnishing sector, in order to realize decorations and protecting degrade.

A further application of the present invention is that of permitting protection of trademarks, thus making it difficult their counterfeiting applying technology on the product, or by creation of specific labels completing and identifying article.

Present invention can also be applied to the art, painting and sculpting sector, wherein said technology can be used, alone or with other materials for realizing works on cloth or sculptures comprised of combustibles materials.

The invention can be further used in further applications both in the civil and military field.

The present invention has been described for illustrative but not imitative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims. 

1. Metallization device (1) for a substrate (2) by metallic material (3), comprising: Means (5) for generating heat suitable to melt said metallic material (3); means (4) for guiding said metallic material (3) suitable to bring said material in correspondence of said heat generating means (5); and means generating compressed air suitable to generate a compressed air jet (A) on said melt metallic material by said heat generation means (5), in order to nebulise the same so as to obtain a jet exiting from an outlet nozzle (6) and cooling nebulised particles of said metallic material (3), said jet exiting from said outlet nozzle (6) being directed on said substrate (2) so as to metalize it and said cooling being such to bring said particles from a melting state to a plastic state and at a temperature lower that the pyrolysis or decomposition temperature of said substrate (2).
 2. Device (1) according to claim 1, characterized in that said heat generation means (5) is of the electric arc kind.
 3. Device (1) according to claim 1, characterized in that said heat generation means (5) are of the oxyacetilenic combustion kind.
 4. Device (1) according to claim 1, characterized in that it comprises cooling means placed in correspondence of said outlet nozzle (6) cooling said exiting jet.
 5. Device (1) according to claim 4, characterized in that said cooling means comprise a serpentine heat exchanger with refrigerating fluid placed in correspondence of the outlet nozzle (6).
 6. Device (1) according to claim 1, characterized in that it comprises heat-adjustment means for adjusting temperature of said outlet jet.
 7. Device (1) according to claim 1, characterized in that said metallic material is a metallic wire (3).
 8. Device (1) according to claim 1, characterized in that said metallic material is dust.
 9. Method for metallization of a substrate (2) comprising the following steps: heating said metallic material (3) bringing it at the fusion temperature; providing a compressed air jet on said melt metallic material (3) so as to nebulize the same material obtaining an outletting jet and cooling the same, said cooling being such to bring said particles from a melt state to a plastic state and at a temperature lower than the pyrolysis or decomposition temperature of said substrate (2); and directing said outlet jet on said substrate (2) to be metalized.
 10. Method according to claim 9, characterized in that it comprises the further steps: further cooling said outlet jet; and heat-adjusting said outlet jet. 